The Japanese company--which currently supplies cells for the Model S and owns a small stake in Tesla--will provide some of the funding for the project, and oversee cell-fabrication operations at the completed plant.

If everything goes as planned, the Model 3 sedan could be joined by a crossover variant sometime after its launch.

Given that Tesla has missed every one of its initial vehicle-launch deadlines to date, it might be prudent to take Musk's current projections with a grain of salt.

Tesla will have to expand production significantly soon, though, to meet Musk's goal of building 500,000 electric cars per year by 2020.

The Model X crossover utility vehicle will be the next step in that expansion; it is expected to help the company double its annual production and achieve its goal of a 100,000-cars-per-year rate as the first increment.